▎ 摘　　要

Ni(OH)(2) nanoflakes were successfully synthesized with a facile hydrothermal method on 3D (three-dimensional) graphene grown by atmospheric pressure chemical vapor deposition (APCVD). The hydrothermal temperature and time were optimized to improve the performance of the composite as a binder-free supercapacitor electrode. The Ni(OH)(2)/3D graphene composite synthesized at 180 degrees C for 3 h shows high specific capacitance of 1450 F/g at a current density of 5 A/g. Even when the discharge current density increases to 60 A/g, a specific capacitance of 1196 F/g is still retained, highlighting the remarkable rate capability of our composite electrode. It also shows good capacity retention of 78 % after 1000 charge-discharge cycles, presenting the excellent cycle stability. These impressive results suggest that the composite is a promising electrode material for high-performance supercapacitors. (C) 2015 Elsevier Ltd. All rights reserved.